Ink-jet printing is a non-impact printing process in which droplets of ink are deposited on a print medium in a particular order to form alphanumeric characters, area-fills, and other patterns thereon. Low cost and high quality of the hardcopy output, combined with relatively noise-free operation, have made ink-jet printers a popular alternative to other types of printers used with computers. Notwithstanding their recent success, intensive research and development efforts continue toward improving ink-jet print quality. A surge in interest in ink-jet printing has resulted in the need to produce high quality prints at a reasonable cost. The challenge remains to further improve the print quality and lightfastness of ink-jet prints. The emerging use of ink-jet prints for digital photos, requires high-resolution images that have accurate color and are durable.
Manufacturers of photographic film and print media have come up with dyes reported to have a display life of up to 60 years. A search of patents by Fuji revealed that they have developed a class of dyes, which when used in photographic media, are very stable. However, this class of dyes has been found not to be very stable toward light. Lightfastness is a very important quality in a dye used in ink-jet printing. Further, it is known that these azopyrazolone dyes can be attacked by ozone at the imine carbon. These shortcoming of such known photographic dyes, especially in the magenta and magenta-containing colors, make them unsuitable for use in ink-jet printing.
Accordingly, investigations continue into developing ink formulations which have improved properties and which do not improve one property at the expense of the others. Thus, there remains a need in the art to further improve the print quality, color gamut, and lightfastness of the ink-jet prints without sacrificing pen performance and reliability, particularly when trying to reproduce the color gamut of silver halide prints.